Abstract
The reaction to the ground and first two levels of has been investigated for proton energies between 6 and 14 MeV. The angular distributions at the highest energies have been analyzed by using a finite range distorted-wave Born-approximation formalism, assuming the two-body force to be of the form , where and refer to the isospin and spin of the incident nucleon, and refer to isospin and spin of the extra-core target nucleons, and is the Yukawa form factor with a range of 1.4 F. Calculations employing Visscher-Ferrell wave functions for and gave a good fit for the → transition and a reasonable value for of 9 MeV. However, the calculations for the → ground-state and second-excited-state transitions yielded inconsistent values for of 7 MeV for the excited transition and 21 MeV for the ground-state transition. This latter result is not unexpected, since is related to the Gamow-Teller -decay operator. The fact that experimentally the () reaction to the ground state is not inhibited (while the corresponding decay is strongly suppressed) indicates that the spin and charge-exchange operator is not sufficient to account for the () ground-state transition. An explanation of the observed ground-state cross section in requires additional spin-flip mechanisms such as a tensor interaction or particle exchange.
- Received 31 March 1967
DOI:https://doi.org/10.1103/PhysRev.160.769
©1967 American Physical Society